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Current consumer virtual reality (VR) systems rely heavily on handheld controllers for input. To this end, numerous methods have been developed and investigated since the emergence of VR in order to improve the user experience for interactions such as gaming or text entry while wearing a head-mounted display (HMD) and using handheld controllers [1, 2]. Although several novel text entry methods have been proposed, there is little research comparing the methods using virtual keyboard interfaces evaluated as experimental conditions. This would allow for a more focused and specialized comparison.Statement of Objective:This work presents the design and empirical evaluation of a split and standard virtual keyboard for text input in virtual environments using handheld controllers. There are numerous applications, including games, for example, entering a gamer’s name or messaging other gamers. An experimental evaluation of two virtual keyboards using VR handheld controllers will be conducted. (Note: As the experiment is ongoing, this abstract is written in the future tense. The final submission will transition to the past tense.) The focus will be on entry speed, accuracy, and efficiency. Both keyboards will be QWERTY-based, but with different organizations. Similar to most physical keyboards, the “standard” keyboard will have all the keys in one arrangement. However, the “split” keyboard will display keys in a split pattern on each side of the screen. For the standard keyboard, users will operate one handheld controller in their preferred hand. For the split keyboard, users will operate one controller in each hand. Thus, a significant point of comparison in the present research is one-handed input vs. two-handed input for the same task. Description of Methods:This research follows an experimental methodology. There will be a total of 14 participants recruited from the local university campus. The study will be a 2 × 5 within-subjects design with the following independent variables and levels:• Keyboard (standard one-handed, split two-handed)• Block (1, 2, 3, 4, 5)The order of testing the keyboards will be counterbalanced to offset learning effects.Five phrases of text will be entered for each block, with phrases selected at random from a standard phrase set [3]. Thus the total number of trials will be 14 participants x 2 keyboards x 5 blocks x 5 phrases/block = 700. The following are the dependent variables in the study:• Entry speed (wpm)• Error rate (%)• Keystroke per character (KSPC)The Unity 3D game engine is used to create the text-input interface installed on the Meta Quest 2 VR headset. Participants will use the Meta Quest handheld controllers to input text. Input uses raycasting, in which the handheld controller casts a virtual line or ray. The virtual ray is positioned on a key on the virtual keyboard, wherein the user presses the trigger on the handheld controller to select the character indicated by the ray.Significance of the Proposed Presentation:The work is significant due to its presentation of the design and experimental evaluation of novel text entry input methods for virtual environments The work pushes the limits of contemporary devices (Meta Quest 2 VR headset) and platforms (Unity 3D game engine) into a design space of particular interest to research in virtual environments.Discussion of Results:Statistical tests, such as the analysis of variance, will be used to identify statistically significant differences between the keyboards for entry speed (wpm), error rate (%), and efficiency using KSPC. Tests for improvement in performance over the five blocks of testing will be included, as well. Regression models will be built using the power law of practice to model the pattern of learning over the blocks of testing. Design implications and suggestions will be offered, as will opportunities for future work. Full details are to be included in the final submission.
To identify if novel/unfamiliar keyboard layouts like OPTI can outperform QWERTY, lengthy training through longitudinal studies is typically required. To reduce this logistical bottleneck, a popular approach in the literature requires participants to type the same phrase repeatedly. However, it is still unknown whether this approach provides a good estimate of expert performance. To validate this method, we set up a study where participants were tasked with typing the same phrase 96 times for both OPTI and QWERTY. Results showed that this approach has the potential to estimate expert performance for novel/unfamiliar keyboards faster than the traditional approach with different phrases. Yet, we also found that accurate estimates still require training over several days and, therefore, do not eliminate the need for a longitudinal study. Our findings thus show the need for research on faster, easier, and more reliable empirical approaches to evaluate text entry systems.
Front-of-Package (FOP) labels highlight important nutrients and help consumers make informed decisions about food purchases. In this study, we investigated consumer comprehension, opinion, and preference associated with two different formats of FOP labels and compared consumer shopping behavior and general trends related to nutrition labeling. Consumer eye-tracking was used for measuring perceived understanding of nutritional information objectively. Results revealed that a color-coded FOP label would garner more attention than a black and white FOP label. Subjects found color-coded FOP labels more straightforward than black and white labels. Participants used the information provided on the FOP for shopping goals. Still, FOPs did not affect objective consumer attention to labels, and labeling schemes did not significantly affect participants’ decisions. Participating subjects did use FOP labels instead of the nutrition facts panels. Still, FOP groups scored lower on a nutrition literacy quiz, indicating that their perceived and actual understanding of nutritional information differed. Our findings suggest that subjects pay attention to FOP labels but do not make decisions.
Text entry by gaze is a useful means of hands-free interaction that is applicable in settings where dictation suffers from poor voice recognition or where spoken words and sentences jeopardize privacy or confidentiality. However, text entry by gaze still shows inferior performance and it quickly exhausts its users. We introduce text entry by gaze and hum as a novel hands-free text entry. We review related literature to converge to word-level text entry by analysis of gaze paths that are temporally constrained by humming. We develop and evaluate two design choices: ``HumHum'' and ``Hummer.'' The first method requires short hums to indicate the start and end of a word. The second method interprets one continuous humming as an indication of the start and end of a word. In an experiment with 12 participants, Hummer achieved a commendable text entry rate of 20.45 words per minute, and outperformed HumHum and the gaze-only method EyeSwipe in both quantitative and qualitative measures.
This paper presents a large-scale dataset on mobile text entry collected via a web-based transcription task performed by 37,370 volunteers. The average typing speed was 36.2 WPM with 2.3% uncorrected errors. The scale of the data enables powerful statistical analyses on the correlation between typing performance and various factors, such as demographics, finger usage, and use of intelligent text entry techniques. We report effects of age and finger usage on performance that correspond to previous studies. We also find evidence of relationships between performance and use of intelligent text entry techniques: auto-correct usage correlates positively with entry rates, whereas word prediction usage has a negative correlation. To aid further work on modeling, machine learning and design improvements in mobile text entry, we make the code and dataset openly available.
The present chapter addresses how the materiality of communication protocols and algorithmic filters of Facebook influence the lifecycle of networked movements, with an emphasis on collective identity, organizational settings, and the potential for mobilization. Drawing on a case study of the anti-Berlusconi protests in Italy between 2009 and 2012, the chapter applies a socio-technical approach grounded in theories of materiality. Such perspective allows the analysis to consider activist communication not merely as a socio-cultural process, but also as a techno-commercial one which considers how marketing-oriented design affects patterns of interaction. The chapter suggests a cycle of depression as a sensitizsing tool to understand the transformation of the temporal dimensions of networked movements. Whereas the algorithmic distribution of information on Facebook promotes short-term mobilization by real-time mass-sharing, on a medium-/long- term basis, it negatively affects collective identity and organizational processes, ultimately hindering mobilization itself. Finally, the study suggests incorporating leadership and collective identity as additional dimensions of analysis to overcome the limitations of existing lifecycle frameworks.
In this paper, we propose a calibration-free gaze-based text entry system that uses smooth pursuit eye movements. We report on our implementation, which improves over prior work on smooth pursuit text entry by 1) eliminating the need of calibration using motion correlation, 2) increasing input rate from 3.34 to 3.41 words per minute, 3) featuring text suggestions that were trained on 10,000 lexicon sentences recommended in the literature. We report on a user study (N=26) which shows that users are able to eye type at 3.41 words per minutes without calibration and without user training. Qualitative feedback also indicates that users positively perceive the system. Our work is of particular benefit for disabled users and for situations when voice and tactile input are not feasible (e.g., in noisy environments or when the hands are occupied).
HaptiVec is a new haptic feedback paradigm for handheld controllers which allows users to feel directional haptic pressure vectors on their fingers and hands while interacting with virtual environments. We embed a 3 by 5 tactile pin array (with an average pin spacing of 25 mm) into the handles of two custom VR type controllers. By presenting directional pressure vectors in eight cardinal directions (N, NE, E, SE, S, SW, W, NW) to users without prior training, they were able to distinguish the correct direction with an accuracy of at least 79%. We illustrate two applications where our device enhances virtual experiences over traditional vibrotactile feedback. In the first application, through the classic first-person shooter Doom, we demonstrate that users can receive directional pressure feedback corresponding to the direction of incident enemy projectiles. In the second application, we demonstrate how our controller can create a more immersive experience by allowing the user to feel their virtual climate by randomizing the directional vectors and presenting the user with "haptic rain" which adapts with the intensity of the rainfall.
This study aims to identify and analyze errors of language aspects that appear on the machine translator from Google-Translate on narrative texts in English into Indonesian. Based on the results of the analysis, it is showed that the morphological aspects occupy the highest positions in the data summary types of errors, as many as 13 errors. Next is the syntactic aspect for 9 errors, and morphology of for 12 errors. It can be concluded that the translation using Google Translate is not the right solution for someone who wants to translate foreign language text, especially if it is used in the learning process at schools.
Technologies for capturing and generating smell are emerging, and our ability to engineer such technologies and use them in HCI is rapidly developing. Our understanding of how these technologies match the experiences with smell that people have or want to have is surprisingly limited. We therefore investigated the experience of smell and the emotions that accompany it. We collected stories from 439 participants who described personally memorable smell experiences in an online questionnaire. Based on the stories we developed 10 categories of smell experience. We explored the implications of the categories for smell-enhanced technology design by (a) probing participants to envision technologies that match their smell story and (b) having HCI researchers brainstorm technologies using the categories as design stimuli. We discuss how our findings can benefit research on personal memories, momentary and first time experiences, and wellbeing.
We conducted four experiments to investigate skilled typists' explicit knowledge of the locations of keys on the QWERTY keyboard, with three procedures: free recall (Exp. 1), cued recall (Exp. 2), and recognition (Exp. 3). We found that skilled typists' explicit knowledge of key locations is incomplete and inaccurate. The findings are consistent with theories of skilled performance and automaticity that associate implicit knowledge with skilled performance and explicit knowledge with novice performance. In Experiment 4, we investigated whether novice typists acquire more complete explicit knowledge of key locations when learning to touch-type. We had skilled QWERTY typists complete a Dvorak touch-typing tutorial. We then tested their explicit knowledge of the Dvorak and QWERTY key locations with the free recall task. We found no difference in explicit knowledge of the two keyboards, suggesting that typists know little about key locations on the keyboard, whether they are exposed to the keyboard for 2 h or 12 years.
We present a study to comparatively evaluate the performance of computer-based 2D and 3D pointing tasks. In our experiments, based on the ISO 9241-9 standard methodology, a Microsoft Kinect device and a mouse were used by seven participants. For the 3D experiments we introduced a novel experiment layout, supplementing the ISO. We examine the pointing devices’ conformance to Fitts’ law and we measure a number of extra parameters that describe more accurately the cursor movement trajectories. Throughput, measured in bits per second is the most important performance measure. For the 2D tasks using Microsoft Kinect, Throughput is almost 39% lower than using the mouse, Target Re-Entry is 10 times up and Missed Clicks count is almost 50% higher. However, for the 3D tasks the mouse has a 9% lower Throughput than the Kinect, while Target Re-Entry and Missed Clicks are almost identical. Our results are also compared to older studies, and we finally show that the Kinect, operated by the user’s hand and voice, is a suitable and effective input method for pointing and clicking, especially in 3D tasks.
The World Wide Web has become a ubiquitous information source and communication channel. With such an extensive user population, it is imperative to understand how web users view different web pages. Based on an eye tracking study of 30 subjects on 22 web pages from 11 popular web sites, this research intends to explore the determinants of ocular behavior on a single web page: whether it is determined by individual differences of the subjects, different types of web sites, the order of web pages being viewed, or the task at hand. The results indicate that gender of subjects, the viewing order of a web page, and the interaction between page order and site type influences online ocular behavior. Task instruction did not significantly affect web viewing behavior. Scanpath analysis revealed that the complexity of web page design influences the degree of scanpath variation among different subjects on the same web page. The contributions and limitations of this research, and future research directions are discussed.
Mobile touch devices have become increasingly popular, yet typing on virtual keyboards whilst walking is still an overwhelming task. In this paper we analyze; firstly, the negative effect of walking on text-input performance, particularly the users' main difficulties and error patterns. We focused our research on thumb typing, since this is a commonly used technique to interact with touch interfaces. Secondly, we analyze how these effects can be compensated by two-hand interaction and increasing target size. We asked 22 participants to input text under three mobility conditions (seated, slow walking, and normal walking) and three hand conditions (one-hand/portrait, two-hand/portrait, and two-hand/landscape). Results show that independently of hand condition, mobility significantly decreased input quality, leading to specific error patterns. Moreover, it was shown that target size can compensate the negative effect of walking, while two-hand interaction does not provide additional stability or input accuracy. We finish with implications for future designs.
Touchscreen phones tend to require constant visual attention, thus not allowing eyes-free interaction. For users with visual impairment, or when occupied with another task that requires a user's visual attention, these phones can be difficult to use. Recently, marks initiating from the bezel, the physical touch-insensitive frame surrounding a touchscreen display, have been proposed as a method for eyes-free interaction. Due to the physical form factor of the mobile device, it is possible to access different parts of the bezel eyes-free. In this paper, we first studied the performance of different bezel menu layouts. Based on the results, we designed a bezel-based text entry application to gain insights into how bezel menus perform in a real-world application. From a longitudinal study, we found that the participants achieved 9.2 words per minute in situations requiring minimal visual attention to the screen. After only one hour of practice, the participants transitioned from novice to expert users. This shows that bezel menus can be adopted for realistic applications.
The impact of Yarbus's research on eye movements was enormous following the translation of his book Eye Movements and Vision into English in 1967. In stark contrast, the published material in English concerning his life is scant. We provide a brief biography of Yarbus and assess his impact on contemporary approaches to research on eye movements. While early interest in his work focused on his study of stabilised retinal images, more recently this has been replaced with interest in his work on the cognitive influences on scanning patterns. We extended his experiment on the effect of instructions on viewing a picture using a portrait of Yarbus rather than a painting. The results obtained broadly supported those found by Yarbus.
Here I try to classify some colour illusions that have been known so far. They include colour constancy, colour illusion of assimilation and contrast, visual completion, visual scission, and colour induction by motion.
Methods for obtaining accurate quantitative assessments of motor impairments are essential in accessibility research, design of adaptive ability-based assistive technologies, as well as in clinical care and medical research. Currently, such assessments are typically performed in controlled laboratory or clinical settings under professional supervision. Emerging approaches for collecting data in unsupervised settings have been shown to produce valid data when aggregated over large populations, but it is not yet established if in unsupervised settings measures of research or clinical significance can be collected accurately and reliably for individuals. We conducted a study with 13 children with ataxia-telangiectasia and 9 healthy children to analyze the validity, test-retest reliability, and acceptability of at-home use of a recent active digital phenotyping system, called Hevelius. Hevelius produces 32 measures derived from the movement trajectories of the mouse cursor, and it produces a quantitative estimate of motor impairment in the dominant arm using the dominant arm component of the Brief Ataxia Rating Scale (BARS). The severity score estimates generated by Hevelius from single at-home sessions deviated from clinician-assigned BARS scores more than the severity score estimates generated from single sessions conducted under researcher supervision. However, taking a median of as few as 2 consecutive sessions produced severity score estimates that were as accurate or better than the estimates produced from single supervised sessions. Further, aggregating as few as 2 consecutive sessions resulted in good test-retest reliability (ICC = 0.81 for A-T participants). This work demonstrated the feasibility of performing accurate and reliable quantitative assessments of individual motor impairments in the dominant arm through tasks performed at home without supervision by the researchers. Further work is needed, however, to assess how broadly these results generalize.
Touch is the predominant method of text entry on mobile devices. However, these devices also facilitate tilt-based input using accelerometers and gyroscopes. This paper presents the design and evaluation of TiltWriter, a non-touch, tilt-based text entry technique. TiltWriter aims to supplement conventional techniques when precise touch is not convenient or possible (e.g., the user lacks sufficient motor skills). Two keyboard layouts were designed and evaluated: Qwerty, and "Custom", a layout inspired by the telephone keypad. Novice participants in a longitudinal study achieved speeds of 12.1 wpm for Qwerty, 10.7 wpm for Custom. Error rate averaged 0.76% for Qwerty, 0.62% for Custom. A post-study extended session yielded 15.2 wpm with Custom, versus 11.5 wpm with Qwerty. Results and participant feedback suggest that a selection dwell time between 700 - 800 ms benefits accuracy.
Studies have shown certain game tasks such as targeting to be negatively and significantly affected by latencies as low as 41ms. Therefore it is important to understand the relationship between local latency - delays between an input action and resulting change in the display - and common gaming tasks such as targeting and tracking. In addition, games now use a variety of input devices, including touchscreens, mice, tablets and controllers. These devices provide very different combinations of direct/indirect input, absolute/relative movement, and position/rate control, and are likely to be affected by latency in different ways. We performed a study evaluating and comparing the effects of latency across four devices (touchscreen, mouse, controller and drawing tablet) on targeting and interception tasks. We analyze both throughput and path characteristics, identify differences between devices, and provide design considerations for game designers.
Cuisine and restaurants are powerful tools for cultural, social and tourist image-building, and projection for tourist promotion, particularly in the case of major tourist places and destinations which boast a well-deserved, long-standing history and reputation for gastronomical beacons. When menus are not properly translated (or transcreated) into a foreign language, restaurants and destinations risk losing not only a huge market, but also damaging their image and reputation. Quality tourism requires excellent products and services, and quality professional menu translation is paramount. Linguistic and psychological aspects affect the way menus are designed, composed, written, and translated, with the aim of enticing diners. This paper aims to analyse the quality of translated restaurant menus in the southern Spanish region of Andalusia, in order to shed some light on the main types of errors found in this key type of text. An empirical study of over one hundred restaurant menus is presented through an error categorisation framework, together with surprising insights from a brief questionnaire for professional menu translators. Finally, a number of proposals and recommendations are offered for better menu translations and a much desired improvement of quality tourist texts.
Although pens and paper are pervasive in the analog world, their digital counterparts, styli and tablets, have yet to achieve the same adoption and frequency of use. To date, little research has identified why inking experiences differ so greatly between analog and digital media or quantified the varied experiences that exist with stylus-enabled tablets. By observing quantitative and behavioural data in addition to querying preferential opinions, the experimentation reaffirmed the significance of accuracy, latency, and unintended touch, whilst uncovering the importance of friction, aesthetics, and stroke beautification to users. The observed participant behaviour and recommended tangible goals should enhance the development and evaluation of future systems.
This chapter reviews the history of input innovations focusing on the Latin alphabet. It considers the difficulties of supporting text entry for ideographic characters, since people in cultures with such graphic characters still have fundamental difficulties in handling those characters. The chapter also introduces future challenges, such as the challenges of various types of selection-based text input interfaces. Further, it discusses some guidelines for the developers of text entry interfaces that can make them more accessible for visually impaired users. Text entry for visually impaired people can be divided into two methods, one for standard keyboard entry used by the majority of users and one for six-dot Braille entry. Though the use of Braille is declining, Braille input is still very important. The chapter reviews the history of these two types of entries. There are several character sets that are grouped under the label of Latin alphabet, but they generally have fewer than 30 basic characters. This characteristic allows laying out a keyboard with individual keys for each character. It means that each physical key is associated with one specific character. This fundamental design of the keyboard allows visually impaired users to use their sense of touch to input text without seeing the keyboard.
The method of calculating Fitts’ throughput is detailed, considering task characteristics, the speed-accuracy trade-off, data collection, and data aggregation. The goal is to bring consistency to the method of calculation and thereby strengthen between-study comparisons where throughput is used as a dependent measure. In addition, the distinction between indirect and direct pointing devices is elaborated using the examples of a mouse as an indirect pointing device and a finger as a direct pointing device. An experiment with 16 participants using a smart phone was conducted as an empirical test of direct touch-based target selection. Overall, the throughput was 6.95 bps. This is a remarkable figure – about 50 % higher than accepted values for a mouse. The experiment included task type (1D vs. 2D) and device position (supported vs. mobile) as independent variables. Throughput for the 1D task was 15 % higher than for the 2D task. No difference in throughput was observed between the supported and mobile conditions.
This chapter discusses text entry using a small number of buttons, focusing on systems in which the user enters text by pressing keys or buttons and in which more than one character or letter is assigned to each button. Such keyboards are ambiguous because there is an uncertainty as to the intended symbol when a key is pressed. There is a recent worldwide interest in such ambiguous keyboards because of mobile computing, for which space is limited. Different keyboards can be designed for different tasks. Even though commercial de facto standard keyboards have predominated in the past, keyboard efficiency has become more important with the widespread adoption of ambiguous keyboards. The chapter presents ways to measure entry efficiency and expect the application of these techniques to lead to a better keyboard design. Even though ambiguous keyboards have a reduced complement of keys, users still require access to a large set of characters, including the alphabet, numbers, symbols, and editing keys.
Mouse control has become a crucial aspect of many modern day computer interactions. This poses a challenge for indi-viduals with motor impairments or those whose use of hands are restricted due to situational constraints. We present a system called the Vocal Joystick which allows the user to continuously control the mouse cursor by varying vocal pa-rameters such as vowel quality, loudness and pitch. A survey of existing cursor control methods is presented to highlight the key characteristics of the Vocal Joystick. Evaluations were conducted to characterize expert performance capa-bility of the Vocal Joystick, and to compare novice user performance and preference for the Vocal Joystick and two other existing speech based cursor control methods. Our results show that Fitts' law is a good predictor of the speed-accuracy tradeoff for the Vocal Joystick, and suggests that the optimal performance of the Vocal Joystick may be com-parable to that of a conventional hand-operated joystick. Novice user evaluations show that the Vocal Joystick can be used by people without extensive training, and that it presents a viable alternative to existing speech-based cursor control methods.
We evaluated tilt as an input method for devices with built-in accelerometers, such as touchscreen phones and tablet computers. The evaluation was empirical and experimental. Sixteen participants performed a tilt-based position-select task, similar to the multi-directional Fitts' law task in ISO 9241-9. Four levels of tilt gain (25, 50, 100, and 200) and two selection modes (first-entry and 500 ms dwell) were used. Movement times were lowest with tilt gain = 50 and first-entry selection. Maximum tilt angles ranged from about 2 ° to 13 °, depending on condition. Tilt as an input primitive is shown to conform to Fitts' law. Throughput is low, however, about 2.3 bits/s for first-entry and 1.2 bits/s for dwell.
Half-QWERTY is a new one-handed typing technique, designed to facilitate the transfer of two-handed touch-typing skill to the one- handed condition. It is performed on a standard keyboard (with modified software), or a special half keyboard (with full-sized keys). In an experiment using touch-typists, hunt-and-peck typing speeds were surpassed after 3-4 hours of practice. Subjects reached 50% of their two-handed typing speed after about 8 hours. After 10 hours, all subjects typed between 41% and 73% of their two-handed speed, ranging from 23.8 to 42.8 wpm. In extended testing, subjects achieved average one-handed speeds as high as 60 wpm and 83% of their two-handed rate. These results are important in providing access to disabled users, and for the design of compact computers.
Since humans direct their visual attention by means of eye movements, a device which monitors eye movements should be a natural “pick” device for selecting objects visually present on a monitor. The results from an experimental investigation of an eye tracker as a computer input device are presented. Three different methods were used to select the object looked at; these were a button press, prolonged fixation or “dwell” and an on screen select button. The results show that an eye tracker can be used as a fast selection device providing that the target size is not too small. If the targets are small speed declines and errors increase rapidly.
Goal items were selected by a series of touch-menu choices among sequentially subdivided ranges of integers or alphabetically ordered words. The number of alternatives at each step, b, was varied, and, inversely, the size of the target area for the touch. Mean response time for each screen was well described by T = k+clogb, in agreement with the Hick-Hyman and Fitts' laws for decision and movement components in series. It is shown that this function favors breadth over depth in menus, whereas others might not. Speculations are offered as to when various functions could be expected.
Workstations require use of the hands both for text entry and for cursor-positioning or menu-selection. The physical arrangement does not allow these two tasks to be done concurrently. To remove this restriction, various alternative input devices have been investigated. This work focuses on the class of foot-operated computer input devices, called moles here. Appropriate topologies for foot movement are identified, and several designs for realising them are discussed.
A new method of estimating the entropy and redundancy of a language is described. This method exploits the knowledge of the language statistics possessed by those who speak the language, and depends on experimental results in prediction of the next letter when the preceding text is known. Results of experiments in prediction are given, and some properties of an ideal predictor are developed.
We examine the usability and performance of Tablet PC direct pen input with a conventional graphical user interface (GUI). We use a qualitative observational study design with 16 participants divided into 4 groups: 1 mouse group for a baseline control and 3 Tablet PC groups recruited according to their level of experience. The study uses a scripted scenario of realistic tasks and popular office applications designed to exercise standard GUI components and cover typical interactions such as parameter selec-tion, object manipulation, text selection, and ink annotation. We capture a rich set of logging data including 3D motion capture, video taken from the participants' point-of-view, screen capture video, and pen events such as movement and taps. To synchronize, segment, and annotate these logs, we used our own custom analysis software. We find that pen participants make more errors, perform inefficient movements, and express frustration during many tasks. Our observations reveal overarching problems with direct pen input: poor precision when tapping and dragging, errors caused by hand occlusion, instability and fatigue due to ergonomics and reach, cognitive differences between pen and mouse usage, and frustration due to limited input capabilities. We believe these to be the primary causes of nontext errors, which contribute to user frustration when using a pen with a conventional GUI. Finally, we discuss how researchers could address these issues without sacrificing the consistency of current GUIs and applications by making improvements at three levels: hardware, base interaction, and widget behavior.
Theoretical models for choice reaction time and discrimination under time pressure must account for Ss’ ability to trade accuracy
for increased speed. The fast guess model views these tradeoffs as different mixtures of “all-or-none” strategies, while incremental
models assume they reflect different degrees of thoroughness in processing the stimulus. Three experiments sought tradeoffs
for difficult visual discriminations, using explicit payoffs to control and manipulate pressures for speed and accuracy. Although
guessing was pervasive, the simple fast guess model could be rejected; Experiments II and III obtained tradeoffs even when
fast guesses were purged from Ss’ data. Tradeoff functions fit by several formulations revealed: (1) slower rates of increase
in accuracy for more similar stimuli, and (2) substantial “dead times” (80–100 msec slower than detection times) before discrimination
responses could exceed chance accuracy. Errors were sometimes faster and sometimes slower than correct responses (depending
on S’s speed-accuracy trade); the latter effect may reflect a ceiling on S’s achievable accuracy. A final discussion examines
implications of the results for models of discrimination under time pressure; it suggests modifications in present models,
focusing on the random walk model, and describes an alternative “deadline” model.
In recent years there has been an increased interest in Human-Computer Interaction Systems allowing for more natural communication
with machines. Such systems are especially important for elderly and disabled persons. The paper presents a vision-based system
for detection of long voluntary eye blinks and interpretation of blink patterns for communication between man and machine.
The blink-controlled applications developed for this system have been described, i.e. the spelling program and the eye-controlled
web browser.
Point-and-click tasks are known to present difficulties to users with physical impairments, particularly motor- or vision-based, and to older adults. This paper presents the results of a study to quantify and understand the effects of age and impairment on the ability to perform such tasks. Results from four separate user groups are presented and compared using metrics that describe the features of the movements made. Distinct differences in behaviour between all of the user groups are observed and the reasons for those differences are discussed.